1 files changed, 86 insertions, 0 deletions
diff --git a/source/blender/simulation/intern/particle_allocator.cc b/source/blender/simulation/intern/particle_allocator.cc
new file mode 100644
index 00000000000..e47a6354d81
--- /dev/null
+++ b/source/blender/simulation/intern/particle_allocator.cc
@@ -0,0 +1,86 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include "particle_allocator.hh"
+
+#include "BLI_rand.hh"
+
+namespace blender::sim {
+
+AttributesAllocator::~AttributesAllocator()
+{
+  for (std::unique_ptr<AttributesBlock> &block : allocated_blocks_) {
+    for (int i : attributes_info_.index_range()) {
+      const fn::CPPType &type = attributes_info_.type_of(i);
+      type.destruct_n(block->buffers[i], block->size);
+      MEM_freeN(block->buffers[i]);
+    }
+  }
+}
+
+fn::MutableAttributesRef AttributesAllocator::allocate_uninitialized(int size)
+{
+  std::unique_ptr<AttributesBlock> block = std::make_unique<AttributesBlock>();
+  block->buffers = Array<void *>(attributes_info_.size(), nullptr);
+  block->size = size;
+
+  for (int i : attributes_info_.index_range()) {
+    const fn::CPPType &type = attributes_info_.type_of(i);
+    void *buffer = MEM_mallocN_aligned(size * type.size(), type.alignment(), AT);
+    block->buffers[i] = buffer;
+  }
+
+  fn::MutableAttributesRef attributes{attributes_info_, block->buffers, size};
+
+  {
+    std::lock_guard lock{mutex_};
+    allocated_blocks_.append(std::move(block));
+    allocated_attributes_.append(attributes);
+    total_allocated_ += size;
+  }
+
+  return attributes;
+}
+
+fn::MutableAttributesRef ParticleAllocator::allocate(int size)
+{
+  const fn::AttributesInfo &info = attributes_allocator_.attributes_info();
+  fn::MutableAttributesRef attributes = attributes_allocator_.allocate_uninitialized(size);
+  for (int i : info.index_range()) {
+    const fn::CPPType &type = info.type_of(i);
+    StringRef name = info.name_of(i);
+    if (name == "ID") {
+      int start_id = next_id_.fetch_add(size);
+      MutableSpan<int> ids = attributes.get<int>("ID");
+      for (int pindex : IndexRange(size)) {
+        ids[pindex] = start_id + pindex;
+      }
+    }
+    else if (name == "Hash") {
+      MutableSpan<int> hashes = attributes.get<int>("Hash");
+      RandomNumberGenerator rng(hash_seed_ ^ (uint32_t)next_id_);
+      for (int pindex : IndexRange(size)) {
+        hashes[pindex] = (int)rng.get_uint32();
+      }
+    }
+    else {
+      type.fill_uninitialized(info.default_of(i), attributes.get(i).data(), size);
+    }
+  }
+  return attributes;
+}
+
+}  // namespace blender::sim